RANKING · 2020 CENSUS · 99 SHOWN OF 99

Fastest growing, Iowa counties · 2020

Iowa counties ranked by population growth from the 2010 census to 2020. This list covers the 99 counties in Iowa that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Dallas County, IAIA118,457+50.7%+13.8 pts

02Johnson County, IAIA160,044+16.8%+1.3 pts

03Polk County, IAIA516,546+14.3%−0.2 pts

04Warren County, IAIA57,331+13.4%+0.5 pts

05Story County, IAIA101,291+10.0%+2.3 pts

06Linn County, IAIA232,028+9.0%−4.6 pts

07Sioux County, IAIA36,774+6.4%+0.8 pts

08Dickinson County, IAIA18,077+6.2%−3.9 pts

09Dubuque County, IAIA99,381+6.0%+2.8 pts

10Scott County, IAIA175,259+5.7%+0.6 pts

11Madison County, IAIA17,270+5.5%−6.8 pts

12Clarke County, IAIA9,574+5.0%−5.2 pts

13Davis County, IAIA9,230+4.1%+1.3 pts

14Washington County, IAIA22,667+4.0%−1.4 pts

15Woodbury County, IAIA106,649+3.7%−2.0 pts

16Lyon County, IAIA12,354+3.0%+4.6 pts

17Bremer County, IAIA25,296+2.9%+0.7 pts

18Plymouth County, IAIA25,697+2.8%−3.4 pts

19Buena Vista County, IAIA20,449+2.8%+0.5 pts

20Calhoun County, IAIA9,562+2.7%+6.1 pts

21Jasper County, IAIA38,153+2.6%−4.3 pts

22Iowa County, IAIA16,504+1.9%−5.2 pts

23Henry County, IAIA19,349+1.7%−4.1 pts

24Boone County, IAIA26,799+1.6%−2.6 pts

25Wayne County, IAIA6,738+1.5%+6.2 pts

26Muscatine County, IAIA41,853+1.1%−3.4 pts

27Pottawattamie County, IAIA92,996+0.5%−5.6 pts

28Marion County, IAIA34,192+0.3%−6.5 pts

29Black Hawk County, IAIA131,532+0.0%−3.4 pts

30Jones County, IAIA21,253+0.0%−4.0 pts

31Cedar County, IAIA18,359+0.0%−4.6 pts

32Carroll County, IAIA20,303-0.3%−0.3 pts

33Wapello County, IAIA35,210-0.5%−1.5 pts

34Mahaska County, IAIA21,880-0.9%−4.6 pts

35Grundy County, IAIA12,361-1.0%−3.8 pts

36Howard County, IAIA9,415-1.0%−2.3 pts

37Ida County, IAIA6,777-1.2%+5.1 pts

38Poweshiek County, IAIA18,368-1.3%−0.2 pts

39Marshall County, IAIA39,890-1.3%−4.0 pts

40O'Brien County, IAIA14,220-1.5%+0.7 pts

41Delaware County, IAIA17,674-1.6%−3.6 pts

42Clay County, IAIA16,202-1.7%−0.5 pts

43Winnebago County, IAIA10,251-1.7%+1.6 pts

44Jackson County, IAIA19,288-1.8%−3.6 pts

45Buchanan County, IAIA20,883-1.9%−3.1 pts

46Allamakee County, IAIA14,238-1.9%−7.8 pts

47Benton County, IAIA26,004-1.9%−14.8 pts

48Mitchell County, IAIA10,650-2.0%−1.5 pts

49Worth County, IAIA7,338-2.0%−1.0 pts

50Wright County, IAIA12,801-2.2%−2.6 pts

51Humboldt County, IAIA9,409-2.2%+1.3 pts

52Harrison County, IAIA14,623-2.3%−8.7 pts

53Cerro Gordo County, IAIA42,372-2.3%−1.7 pts

54Adair County, IAIA7,403-2.4%−0.4 pts

55Webster County, IAIA36,838-2.7%−2.4 pts

56Lucas County, IAIA8,847-3.0%−6.8 pts

57Guthrie County, IAIA10,782-3.0%−6.8 pts

58Union County, IAIA11,829-3.2%+0.3 pts

59Pocahontas County, IAIA6,819-3.2%+5.9 pts

60Crawford County, IAIA16,237-3.3%−4.3 pts

61Cherokee County, IAIA11,369-3.4%+4.1 pts

62Chickasaw County, IAIA11,663-3.4%−1.9 pts

63Shelby County, IAIA11,689-3.5%−3.0 pts

64Des Moines County, IAIA38,077-3.5%−2.9 pts

65Tama County, IAIA16,796-3.6%−7.5 pts

66Butler County, IAIA14,049-3.6%−0.9 pts

67Hardin County, IAIA16,455-3.7%−2.3 pts

68Montgomery County, IAIA10,002-3.8%−1.3 pts

69Mills County, IAIA14,793-3.8%−14.0 pts

70Hamilton County, IAIA14,944-4.0%−6.3 pts

71Floyd County, IAIA14,901-4.1%−3.2 pts

72Osceola County, IAIA5,980-4.2%−0.5 pts

73Appanoose County, IAIA12,077-4.4%−4.3 pts

74Palo Alto County, IAIA8,899-4.5%+0.4 pts

75Page County, IAIA14,856-4.5%−5.2 pts

76Keokuk County, IAIA9,797-4.5%−2.6 pts

77Kossuth County, IAIA14,322-4.6%+3.1 pts

78Winneshiek County, IAIA19,733-4.7%−6.9 pts

79Hancock County, IAIA10,528-4.8%−0.6 pts

80Louisa County, IAIA10,416-4.8%−9.9 pts

81Van Buren County, IAIA7,131-4.8%−6.6 pts

82Monroe County, IAIA7,406-4.9%−3.7 pts

83Sac County, IAIA9,525-5.2%+1.3 pts

84Monona County, IAIA8,539-5.3%−5.2 pts

85Clinton County, IAIA46,002-5.4%−3.7 pts

86Cass County, IAIA12,960-5.9%−3.0 pts

87Clayton County, IAIA16,845-6.0%−4.0 pts

88Greene County, IAIA8,658-6.1%−9.2 pts

89Franklin County, IAIA9,868-6.2%−0.4 pts

90Lee County, IAIA32,306-6.4%−4.8 pts

91Fayette County, IAIA19,047-6.6%−7.3 pts

92Taylor County, IAIA5,835-6.7%−4.5 pts

93Jefferson County, IAIA15,291-7.0%−6.2 pts

94Audubon County, IAIA5,509-7.3%−0.4 pts

95Adams County, IAIA3,617-8.1%−0.2 pts

96Emmet County, IAIA9,107-8.9%−4.2 pts

97Ringgold County, IAIA4,642-9.1%−10.0 pts

98Decatur County, IAIA7,655-9.6%−13.8 pts

99Fremont County, IAIA6,522-11.2%−8.6 pts

SHOWING 1–99 OF 99

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UPDATED 2026-08-08 · DATA: US CENSUS BUREAU DECENNIAL CENSUS